It has been known in the art related to treatment of sausage products to artificially impart smoke flavor to frankfurters and other sausage products. While several methods have been proposed in the past for imparting smoke color to frankfurters, it is believed that, in addition to the use of the natural smoke of burning wood, there presently are two methods in commercial use. In both of these, natural-liquid smoke is utilized rather than dye. The liquid smokes are derived from recovery of smoke from burning wood by scrubbing of the smoke with water. In one of these, the stuffed frankfurters are exposed to an atmosphere saturated with vapor phase smoke or in the second alternative the frankfurters are sprayed with a liquid smoke or dipped in a bath containing liquid smoke. While these processes are successful, there are certain economic disadvantages. There is a need for a reduced cooking cycle time, reduced labor cost and increased consistency of color development. Further, there are some meat batters difficult to color with vapor phase or liquid smoke.
Further, it has been known to color frankfurters by use of a transfer casing which has been impregnated with Red 40 or Yellow 6. However, such frankfurters only have limited appeal in that the red frankfurters are only widely sold in the Southeastern U.S. and the Yellow 6 colored (orange) frankfurters are only widely sold in some areas of the Southwestern U.S. Attempts have been made to color frankfurters with combinations of legal Food and Drug Administration approval colors (FD&C colors). However, these colors have been found to differentially diffuse into frankfurters with a result in changes in color within a few days of refrigerator storage and the frankfurter usually takes the surface color of the slowest diffusing component within a few days.
U.S. Pat. Nos. 4,104,408, 4,171,381, 4,196,220, 4,216,574 and 4,278,694 to Chiu are directed to various means of coating food product casings with colorant and/or flavoring material. They are primarily directed to interior coating rather than exterior. Interior coating is difficult for small diameter casings as there is no way to efficiently patch the small casings where the coating slugs are inserted and removed and it significantly increases labor costs. Further, interior coating methods have difficulty in that when the casing is shirred, the colorant tends to pool in the open loops of the pleats. The liquid smoke derived colorants of U.S. Pat. Nos. 4,196,220 and 4,278,694 are not believed suitable for exterior coating with penetration of the coating to the meat product therein.
There remains a need for an improved system of coloring for applying smoke color to encased meat products such as sausages, bologna, salami, hams and frankfurters. There is a need for a smoke color that will transfer from casing to meat batter during cooking and remain on the surface of the meat batter after the casing is removed. There is a need for a smoke color which will not bleed excessively or change color when the sausage is reheated. There is a continuing need for a smoke colorant which may be applied to unstuffed casings, from the outside, at normal production line speeds, without any more labor than attended to a casing dyed with a food color such as Yellow 6 or Red 40. There also is a need for a smoke color which will be evenly distributed on the meat product surface whereas those coated by vapor phase smoke may show marks from where the meat rested on the support stick or was in contact with other frankfurters. Further, there is a need for a colorant which may be applied to the outside of a casing which is stable during the shirring process. There is a further need for an improved colorant which will not interfere with any food casing processing subsequent to its application to the casing such as drying, reeling, shirring, stuffing, linking or peeling and which further will contain a colorant which will have sufficient shelf life for commercial distribution.